1. Field of the Invention
The present invention relates to a vehicle suspension apparatus which dampens movement of a wheel up and down to relieve an input from a road surface, in order to secure the stability of a vehicle.
2. Description of the Related Art
As a suspension apparatus for a vehicle, there is known a suspension apparatus of a double wishbone type or of a multi-link type.
This type of vehicle suspension apparatus is generally employed in such a manner that the design thereof is changed according to uses.
As a vehicle suspension apparatus of this type, there is known a suspension apparatus of a multi-link type which is used to support the rear wheels of a vehicle (for example, JP-A-2005-225382, Page 15, FIG. 2)
Now, description will be given below of the outline of a technology disclosed in JP-A-2005-225382 with reference to FIG. 7.
FIG. 7 is an explanatory view of the basic structure of a conventional suspension apparatus for a vehicle.
Specifically, this vehicle suspension apparatus 210 includes:
a knuckle 212 for mounting a rear wheel 211 thereon,
an upper arm (a first lateral arm) 213 extending outwardly in the width direction of a vehicle body from a vehicle body frame (not shown) for supporting the upper part of the knuckle 212,
a lower arm (a second lateral arm) 214 extending outwardly in the vehicle width direction from the vehicle body frame for supporting the lower part of the knuckle 212,
a control arm (a third lateral arm) 215 extending outwardly in the vehicle width direction from the vehicle body frame at a height between these upper and lower arms 213 and 214 for supporting the knuckle 212,
a leading arm 216 extending forwardly of the vehicle body from the vehicle body frame for supporting the knuckle 212, and
a trailing arm 217 extending backwardly of the vehicle body from the vehicle body frame for supporting the knuckle 212.
The trailing arm 217 is swingably supported on the vehicle body side through a rubber bush (not shown) and is also swingably supported on the knuckle 212 side through a rubber bush (not shown). The remaining arms 213 to 216 also include rubber bushes on the vehicle side and on the knuckle side.
However, in the vehicle suspension apparatus 210, the number of rubber bushes for swingably supporting the arms 213 to 217 is large. This increases the portions of the rubber bushes that are flexed greatly when the suspension is stroked. Also, this increases the portions of the rubber bushes that must secure the large hysteresis of the rubber bushes, which makes it necessary to increase the outside diameters of the rubber bushes. The increase of the portion may result in the increased weights of the rubber bushes and thus weight of the vehicle suspension apparatus.
Also, the vehicle suspension apparatus 210 occurs an expected vibration absorbing mechanism which may raise a cause to worsen the driving feeling of the vehicle due to the deflection amount of the rubber bush is large.